JPH04309104A - Air-actuated system having dynamic self-monitoring function - Google Patents

Abstract

PURPOSE: To improve a safety protecting function by detecting mutual deviation between sequences of control valve elements by a monitor means, detecting malfunction of the monitor means by a self-monitoring means, and stopping the operation of a control system. CONSTITUTION: This system is provided with monitor valves 30 and 32 which stop the further operation of the control system 10 by detecting the disorder of the movements of the sequences of the control valve elements 46 and 48 of a double safety control valve assembly 12 as a monitor system for a pneumatic system. Further, a monitor subsystem of the control system 10 monitors the periodic operations of pilot valves 16 and 18 and monitor valves 30 and 32 and stops the operation of the control system 10 itself even if the periodic operation stops. A capacity chamber 50 stores compressed air by some amount to serve as a buffer means which prevents the operation of the control system 10 from stopping even when the valve element 38 sticks momentarily or operates slow. Consequently, the safety protecting function of the monitor system of the pneumatic control system can be improved.

Description

[Detailed description of the invention]

0001

FIELD OF INDUSTRIAL APPLICATION This invention relates generally to pneumatic double safety valves of the type used to control pneumatically actuated clutches and/or brakes for press equipment, or other pneumatically actuated devices of this type. Concerning a monitor system for.

0002

BACKGROUND OF THE INVENTION To improve the safety of pneumatically operated devices such as embossing presses or similar devices, a dual safety valve assembly is provided between a compressed air inlet and a supply to the pneumatically operated device. There is. In such devices, compressed supply air will not be supplied to the pneumatically actuated device from the compressed air inlet unless both valve elements of the dual safety valve are in the open position. The intent of such devices is to prevent continued operation of the pneumatically actuated device if one of the valve elements malfunctions.

0003

However, due to various factors or characteristics often found in such devices, even when one of the valve elements gets stuck in an incorrect position or otherwise malfunctions, the pneumatically actuated device Sometimes it works imperfectly. Whether such undesirable malfunctions can occur depends, in part, on whether the malfunctioning valve becomes stuck in its closed or open position. If it is in the closed (ie, drain) position, it is less likely that the remaining valves will be able to continue operating or operating the system. However, if a stuck valve is in its open position, the remaining operable valves may sometimes continue to operate the device at least partially, depending on the arrangement of the system in question. In such cases, the operator may not be aware of the malfunction or faulty condition of one of the valve elements unless a suitable monitoring system is present. In other situations, when one of the valve elements is in a stuck or otherwise impaired condition,
Normal operation will not continue, but the pneumatically actuated device may unexpectedly and undesirably move incompletely from a safe condition to an unsafe condition. This type of malfunction occurs without any warning and can result in serious injury to people or property.

[0004] Accordingly, it would be advantageous and important to provide some type of monitoring system to inform the operator that one or both of the valve elements are in a stuck or otherwise impaired condition. Numerous examples of dual safety valve devices with and without monitoring systems are found in the prior art, such examples being disclosed in U.S. Pat. No. 2,906
, No. 246, No. 3,757,818, No. 3,858
, No. 606, reissue No. 28,250, No. 4,181,
No. 148, No. 4,257,255, No. 4,345,6
No. 20 and No. 4,542,767. The disclosure of these reference examples is for the purpose of providing a background for the present invention.
Incorporated herein by reference.

In addition to the above, in pneumatic systems including dual safety valves of the type discussed herein, a monitoring system is provided for the purpose of preventing undesirable or unsafe continuous operation or incomplete operation of the pneumatically actuated device. , including features intended to produce a safe deactivation of the pneumatic system. However, some such monitoring systems do not adequately provide for such safe deactivation of the system in all cases. Examples of such monitoring systems are those that cannot detect stuck or sluggish valve elements, those that cannot detect total or partial malfunctions of the monitoring system itself, or malfunctions of dual safety valves or monitoring systems. This includes failure to provide adequate safety protection for operation of pneumatically actuated devices when the reset function is activated without first properly correcting the reset function.

[0006]Therefore, what is needed is a dual safety valve system that provides adequate monitoring to prevent further operation of the pneumatic actuator in the event that either of the valve elements of the dual safety valve is out of sequence with respect to the other valve element. The need has arisen. In addition to this, it is an object of the present invention to provide adequate safeguards to prevent further activation in the event of a jam or other malfunction of the monitor valve element with unacceptable sluggish movement or of the monitor system itself. . Thus, the present invention seeks to provide a dual safety valve monitoring device for a pneumatic system that is self-monitoring with respect to both the dual safety valve and the monitoring system itself.

The invention further provides for a monitor that is constantly in motion during operation of the system to substantially reduce the possibility of a faulty, stuck or sluggish valve element within the monitor system itself. The aim is to provide a system. Yet another object of the present invention is that the amount of sluggishness or lag of a valve element that is allowed before causing system deactivation can be preselected or varied to suit the design factors of a given device. The aim is to provide a monitoring system that allows

Other objects, advantages, and features of the invention will become apparent from the following description and appended claims when taken in conjunction with the accompanying drawings.

[0009]

SUMMARY OF THE INVENTION To this end, a dynamic self-monitoring pneumatic system according to the present invention comprises an inlet, an outlet, an outlet and at least one pair of control valve elements, as illustrated in the accompanying drawings. has a control valve assembly with
Each said control valve element has at least two valves for controlling the flow of compressed air between said inlet and outlet and said outlet and outlet.
In a monitoring system for a pneumatic control system, the control valve elements are movable between two positions and the control valve elements are moved together in sequence with each other between each of the positions. monitoring means for detecting relative movement of the control valve element and preventing further operation of the control system in response to detection of out-of-sequence movement of the control valve element; and detecting malfunction of the monitoring means. and self-monitoring means for preventing further operation of the control system in response to detection of the malfunction of the monitoring means.

[0010] In the above invention, the monitor means includes at least one pair of monitor valve elements having port means therein, and the monitor valve elements are arranged between at least one pair of valve operating positions during normal operation. movable together in sequence with each other, said monitoring means for moving said monitor valve element to an out-of-sequence position in response to detection of out-of-sequence movement of said control valve element; and said monitor valve element; Preferably, the monitor valve elements include communication means for connecting the monitor valve elements to prevent further operation of the control system when the monitor valve elements are out of sequence with each other.

[0011] The invention according to item 1 also provides that the monitor means includes at least one pair of monitor valve elements having port means therein, and during normal operation, the monitor valve elements are arranged at each of the at least one pair of valve operating positions. and said self-monitoring means connect said monitor valve elements for preventing further operation of said control system when said monitor valve elements are out of sequence with respect to each other. It is preferable to include a communication means for communicating.

[0012] In the invention described in the preceding two items, it is preferable that under normal conditions, the monitor valve element moves in sequence with each other each time the control valve element moves together in sequence with each other.

[0013] The invention according to item 1 also provides a method for preventing further operation of the control system as a result of detection of relatively out-of-sequence movement of the control valve element or malfunction of the monitoring means. Preferably, it further includes means for delaying by a predetermined time.

Preferably, the invention as set forth in item 1 further comprises means for preventing restart of operation of the control system when the control valve element or the monitor valve element is out of sequence with respect to each other.

[0015]

The monitoring means of the present invention detects any out-of-sequence movement of the control valve element and prevents further operation of the control system; It detects this and stops further operation of the control system. In this way, further operation of the control system is prevented not only when the sequence of the control valve elements is out of order, but also when the monitoring means itself malfunctions, thereby significantly improving the safety protection effect. do.

The monitoring means includes at least one pair of monitor valve elements movable between at least one pair of valve actuation positions, the monitor means moving the monitor valve elements in response to detection of out-of-sequence movement of the control valve elements. means for moving the monitor valve elements to an out-of-sequence position and communication means for connecting the monitor valve elements to prevent further operation of the control system when the monitor valve elements are out of sequence with each other; As the control valve elements move in sequence with each other, each monitor valve element also moves in sequence with each other. In this way, since the monitor valve element moves as the control valve element moves, its movement is performed frequently, reducing malfunctions of the monitor means due to sticking, etc., and further improving the safety protection effect.

The monitoring means also includes at least one pair of monitor valve elements movable between at least one pair of valve actuation positions, and the self-monitoring means is configured to control further control system operations when the monitor valve elements are out of sequence with respect to each other. If the control system includes a communication means connecting the monitor valve element for preventing the operation of the control system, further operation of the control system can be reliably prevented even if the monitor means itself malfunctions due to stalemate or the like.

Furthermore, if the monitor valve elements are moved in sequence with each other every time the control valve elements move together in sequence with each other, the safety protection effects described in the preceding two items can be further ensured.

and further comprising means for delaying, for a predetermined period of time, prevention of further operation of the control system as a result of detection of relatively out-of-sequence movement of the control valve element or malfunction of the monitoring means. According to the
Deactivation of the control system can be delayed by a predetermined amount of time, depending on system component tolerances, design factors, etc., thereby avoiding premature deactivation.

[0020] The control system further includes means for preventing restart of operation of the control system when the control valve elements or the monitor valve elements are out of sequence with respect to each other. There is no risk of re-activation and the safety protection effect is further improved.

[0021]

1-11 diagrammatically illustrate an exemplary dynamic self-monitoring pneumatic system or control system 10 in accordance with the present invention, including variations discussed below. Those skilled in the art will readily appreciate that the illustrated control system 10 is solely for the purpose of illustrating the principles of the present invention. Those skilled in the art will also readily appreciate that the principles of the invention are equally applicable to pneumatic actuation or control systems other than those illustrated for purposes of illustration.

FIGS. 1 and 2 illustrate a normal operating mode or state of a typical control system 10 in which no malfunctions have occurred. The basic components of the control system 10 are a compressed air source 11 and a press clutch/brake mechanism 1
4 or similar mechanisms for operating pneumatically actuated devices. Other basic components of control system 10 include a pair of monitor valves 30 and 32, a pair of pilot valves 16 and 18;
It includes a volume chamber 50 as well as a lockout/reset valve 40. Dual safety control valve assembly 12 is connected to inlet port 51
, an outlet port 52, and an evacuation port 55. The inlet and outlet ports 51 and 52 are opened and closed by cross-flow passageways 53 and 54 that are opened and closed to provide or prevent fluid communication between the inlet and outlet ports 51 and 52, respectively, by movement of the poppet valve elements or members 46 and 48. , are interconnected. Poppet valve element 4
6 and 48 is effected by respective piston/exhaust valve combinations 27 and 28 which, as well as the elastic biasing forces of return springs 29 and 31, are driven by the pilot valves 16 and 18. are activated or deactivated by supplying or discharging compressed pilot air from, respectively.

Each poppet valve member 46 and 48 has three control valve sections 39, 41 (poppet valve sections), 37, 3, respectively.
8 (sliding valve part) and 27, 28 (piston/exhaust valve assembly), and there is a cross flow between the first control valve part 39, 41 and the second control valve part 37, 38, respectively. An intermediate pressure region is formed in which passages 53 and 54 are communicated. Each poppet valve member 39 and 41 controls communication between the corresponding intermediate pressure region and the inlet port 51, and closes this communication when each poppet valve member 46 and 48 is inactive and closed (exhaust position); When it becomes open (supply position), this communication is opened. Each sliding valve member 37 and 38 controls communication between the outlet port 52 and a cross-flow passageway 53 and 54 that is substantially part of the opposite intermediate pressure region, and each poppet valve member 46 and 48 is inoperative. When , this communication is closed, and when activated, this communication is opened. Piston/exhaust valve assemblies 27 and 28 control communication between outlet port 52 and exhaust port 55, opening this communication when each poppet valve member 46 and 48 is inactive, and closing this communication when actuated. .

Monitor valve 30 preferably includes a pair of passage ports 56 and 57 whose positions are controlled by pneumatic actuators 33 and 34. Similarly, monitor valve 32 includes through ports 58, 59, 60, and 61 whose positions are controlled by pneumatic actuators 35 and 36.

Pilot valves 16 and 18 each have a pair of passage ports 62 and 63 whose positions are controlled via solenoids 20 and 22 or similar known valve actuation devices, as well as respective return springs 24 and 26; 64 and 65.

Lockout/reset valve 40 preferably includes a number of passage ports 91 , 92 , 93 and 94 whose positions are controlled by manual element 42 and return spring 44 . As discussed in further detail below, the lockout/reset valve 40 operates to reset the control system 10 to its correct normal operating condition after a malfunction or fault condition has occurred and been corrected. be done.

The ports of each element of control system 10 are connected to each other by a number of compressed air lines, each of which is described below in connection with a description of its function in the description of the operation of control system 10. be identified.

The control system 10 initially operates, as shown in FIG. 1, with the press or other control device either inactive or in normal operation and in the exhaust mode, so that compressed air is not supplied to the press clutch. / is in a non-supply operating mode where the brake mechanism 14 is discharged. This state is such that piston/exhaust valve complexes 27 and 28 are in their open positions, respectively, providing fluid communication between press clutch/brake mechanism 14 and exhaust port 55 via conduit 69 and outlet port 52. As a result of the position of poppet valve members 46 and 48,

Additionally, pilot valves 16 and 18 are based on solenoids 20 and 22, respectively, in the "inactive" position.
, compressed air source 11 is in communication with volume chamber 50, while volume chamber 50 supplies compressed air to pneumatic actuators 34 and 36 to maintain monitor valves 30 and 32, respectively, in their left hand positions. . Such fluid communication between compressed air source 11 and volume chamber 50 is provided via lines 70, 72 and 74, port 92 of lockout/reset valve 40, and ports 57 and 58 of monitor valves 30 and 32. 76, 77, 78, 79 and 88. Fluid communication between volume chamber 50 and pneumatic actuators 34 and 36 is provided by line 87 and port 91 of lockout/reset valve 40.
, and the conduit 75. However, as can be seen in the diagram of FIG. 1, since the pilot valves 16 and 18 are in the left-hand position, lines 80 and 79 are blocked, which allows compressed air to pass through the volume chamber 50 through the monitor valves 30 and 32. The compressed air communication path from the source 11 to the pneumatic actuators 34 and 36 is assumed to be "closed". This, on the one hand, maintains monitor valves 30 and 32 in their left-hand position as diagrammatically shown in FIG. Additionally, this prevents pilot air from flowing through lines 81 and 82;
This prevents poppet valve elements 46 and 48 from operating to their open positions and prevents flow from inlet port 51 to outlet port 52 through cross-flow passages 53 and 54.

As shown in FIG. 2, solenoids 20 and 2
2 is energized to its "active" condition, each pilot valve 16 and 18 is switched to its right-hand position as seen in FIG. Fluid communication is provided through the piston/exhaust valve complexes 27 and 28, respectively. This fluid communication is provided by port 62 of pilot valve 16 in alignment with conduits 80 and 82 to provide compressed air that forces poppet valve element 46 downwardly against the force of return spring 29. Similarly, port 64 of pilot valve 18 provides fluid communication between conduit 79 and conduit 81 to provide fluid communication between piston/exhaust valve complex 28 and poppet valve element 48 against the force of return spring 31.
Supply compressed air to press down. Such a condition may cause poppet valve elements 46 and 48 to cause dual safety control valve 12
results in opening fluid communication between inlet port 51 and outlet port 52 and closing communication between outlet port 52 and exhaust port 55 of. As a result, the compressed air is transferred to the control valve 12.
monitor ports 83 and 84 are also connected to pneumatic actuators 33 and 35 of monitor valves 30 and 32 via air lines 85 and 86, respectively, to which compressed air is supplied. supply.

The pneumatic actuators 33 and 35 are designed to be larger than, or in any case to overcome, each of the opposite pneumatic actuators 34 and 36, so that the compressed air Pneumatic actuator 3
3 and 35, the monitor valves 30 and 32 are switched to the right as viewed in FIG. Monitor valve 30
Such a rightward switching of and 32 has the result that compressed air from the compressed air source 11 is continuously supplied to the piston portions of the piston/exhaust valve combinations 27 and 28 of the control valve 12. Such continuous supply of compressed air is monitored by lines 70, 72 and 74, through port 92 of lockout/reset valve 40, through lines 76, 90 and 78, and through each line 81 and 82, respectively. This is done by passage ports 59 and ports 56 of valves 30 and 32. In such a state, the volume chamber 50
is continuously supplied with compressed air via lines 78, 79 and 88. Volume chamber 50 continues to supply compressed air to pneumatic actuators 34 and 36 by conduits 87 and 75 and through port 91 of lockout/reset valve 40; This supply is overcome by the forces acting on each monitor valve 30 and 32 as a result of the compressed air being supplied to pneumatic actuators 33 and 35, respectively.

In FIGS. 1 and 2, each solenoid 20
and 22 are placed in their "inoperative" state as shown in FIG. 48 is allowed to move upwardly to evacuate the press clutch/brake mechanism 14 via conduit 69, exit port 52, and evacuation port 55. At the same time, at least the piston/exhaust valve complex 27
and 28, the valve sections 37 and 38 of the poppet valve assemblies 46 and 48, respectively, are not fully closed, thereby preventing the monitor ports 83 and 84, the conduits 85 and 86, and thus the pneumatically actuated device. A predetermined amount of leakage is allowed to drain 33 and 35, respectively. As a result, the compressed air accumulated in the volume chamber 50 causes the pneumatically actuated device 34 of each monitor valve 30 and 32 to
and 36 become conditioned to overcome the forces of the respective pneumatic actuators 33 and 35, thereby switching the monitor valves 30 and 32 to their respective left hand positions as shown in FIG. At this point in operation, control system 10 returns to its discharge or stop condition, as shown in FIG. 1, and solenoids 20 and 2
By re-energizing 2 as described above, operation is resumed and the supply state shown in FIG. 2 is ready.

Thus, a complete, normal operating cycle of control system 10, as described above in connection with FIGS. 1 and 2, has been disclosed. Each such complete cycle of operation includes a complete cycle of movement of poppet valves 46 and 48 of control valve 12 as well as pilot valves 16 and 18.
It is important to note that this includes, of course, complete rightward and leftward movement of each monitor valve 30 and 32. The complete rightward and leftward periodic movement of monitor valves 30 and 32 results in the dynamic nature of the self-monitoring subsystem of control system 10. Such continuous movement of monitor valves 30 and 32 not only greatly contributes to their proper operation and eliminates their tendency to become stuck in one position, but also greatly facilitates this monitor valve sub-operation, as will be discussed in more detail below. It functions to allow the system to have self-monitoring capabilities.

FIGS. 3 and 5 illustrate malfunctions that occur as a result of sticking or unacceptably slow sluggish movement of one of the poppet valve members 46 or 48, such as when one poppet valve is out of sequence relative to the other. That is, it illustrates two alternative forms of a state in which a failure has occurred. In FIG. 3, solenoids 20 and 22 have been placed in their "inactive" state and have therefore been signaled to return to the drain or stop state shown in FIG. However, instead of returning to its ejection position, the poppet valve assembly 48 is stuck, or in any case left in its "open" or dispensing condition. Dual safety control valve 12 thus has inlet and outlet ports 51 and 52, respectively, as a result of outlet port 52 being in communication with discharge port 55.
The press clutch/brake mechanism 14 functions to substantially prevent compressed air from the compressed air source 11 through the press clutch/brake mechanism 14 . Without the monitoring subsystem described above, reactivation of solenoids 20 and 22 would again move poppet valve assembly 46 to its "open" or supply position, thereby allowing continuous full operation of press clutch/brake mechanism 14. or allow incomplete operation. However, the functionality of the monitor subsystem prevents such an outcome and the control system 10 is safely shut down and
Alerts the driver of a malfunction or failure condition.

[0035] Such a blockage is achieved by inlet 51 and open cross-flow passage 5 in the condition shown diagrammatically in FIG.
3 and led to the pneumatically actuated device 35 through the monitor port 84 and the conduit 86;
This compressed air therefore maintains the monitor valve 32 in its rightward switching position. As a result, port 59 of monitor valve 32 remains aligned with conduit 90, but conduit 90 is closed with monitor valve 30 in the correct leftward switching position.
Compressed air from source 11 is supplied to pilot valves 16 and 18.
or prevent it from flowing into the volume chamber 50. Similarly, port 57 of monitor valve 30 is correctly switched to the left.
connects lines 78, 79 and 88 to line 77 and port 58 of monitor valve 32 switched to the right;
Volume chamber 50 is likewise evacuated, so that monitor valve 30 remains in its leftward position.

Reactivation of solenoids 20 and 22 to move pilot valves 16 and 18 to the right when system 10 is in the state shown in FIG.
are connected to respective lines 80 and 79 via ports 62 and 64 of pilot valves 16 and 18, respectively, which in turn connect to line 78, port 57 of monitor valve 30, line 77, and It is connected to each discharge via port 58 of monitor valve 32. This results in preventing pilot air pressurization of lines 81 and 82, thereby preventing poppet valve assembly 46 from being moved downwardly toward its "open" or dispensing position. Therefore, the functioning poppet valve assembly 46 is not moved when the control system 10 is in the state shown in FIG. System 10 includes poppet valve assembly 4
8 is deactivated and rendered inoperable as a result of a malfunction or fault condition.

However, in connection with the malfunction condition illustrated in FIG. 3, such safe deactivation of system 10 may also occur in response to a mere sluggish response of valve element 38 that is not a complete stalemate of valve element 38. It should be noted that However, in order to avoid premature shutdown, to act as a buffer for the system, and to accommodate normal tolerances of system components or other design factors of a given device, A quantity of compressed air is stored in the volume chamber 50, which of course depends on the preselected size of the volume chamber 50. As a result, the evacuation from the volume chamber 50 described above does not occur instantaneously, and therefore the accumulated compressed air within the volume chamber 50 is discharged either after a momentary stagnation or after a slow sluggish movement. When later returned to its discharge position, actuator 36 functions for a predetermined time to move monitor valve 32 to the left. However, if such sticking of the valve element 48 is too long, or if its movement is too slow, the volume chamber 50 will be drained to the point where its pressure can no longer actuate the actuator 36, so that the monitor Valve 32 will no longer be able to switch to the left, thereby causing the system 10 to shut down as described above.

As discussed above, by selectively sizing the volume chamber 50, the system can be selectively pre-configured to accommodate an acceptable level of sticking or sluggish movement of the valve member of the dual safety valve 12. can be adjusted and without causing premature undesired deactivation.
Tolerances of system components, desired system sensitivity,
It can be adapted to different component dimensions or other design factors. In at least some embodiments, the volume chamber 50 may be modified to correspondingly change the deactivation response of the monitoring subsystem if such factors or other design factors are changed or adjusted.
are made arbitrarily interchangeable.

FIG. 5 shows that a malfunction or failure due to sticking, improper sluggish movement, or other upward movement obstruction of the poppet valve assembly 46 in an out-of-sequence relationship with respect to the poppet valve assembly 48. This shows a similar response to the situation. As a result of a stuck or other malfunction of the poppet valve assembly 46, the monitor valve 30 is held in the leftward switching position in the same manner as described above in connection with FIG.
By switching the correctly functioning monitor valve 32 to the left,
Compressed air from compressed air source 11 is prevented from flowing to pilot valves 16 and 18 in the same manner as described above in connection with FIG. Similarly, lines 81 and 82 for actuating piston/exhaust valve complexes 28 and 27, respectively, are
The left-switched pilot valves 16 and 18 are connected to the exhaust via ports 63 and 65, respectively. Even if an attempt is made to actuate control system 12 by energizing solenoids 20 and 22, these lines 81 and 82, respectively,
through ports 62 and 64 of ports 6 and 18, lines 78, 79, and 80, port 56 of monitor valve 30 switched to the right, line 90, and port 61 of monitor valve 32 switched to the left. and remains connected to the exhaust. In the situation shown in FIG. 5, the volume chamber 50 is also evacuated in the same manner as described in connection with FIG. Thus, as discussed above in connection with FIG. 3, the control system 10 is deactivated in response to a malfunction or fault condition of the poppet valve assembly 46, and the volume chamber 50 is pre-empted by the valve element 46 as described above. It functions to tolerate a selected amount of slow motion or stagnation time.

Actuation of reset/lockout valve 40 via manual element 42 in either the condition shown in FIG. 3 or the condition shown in FIG.
The control system 10 will not be operable as long as one of the malfunctioning or faulty conditions indicated in . This is due to the features of the self-monitoring system shown in FIGS. 4 and 6, respectively.

As shown in FIGS. 4 and 6, manual element 42
Leftward movement of reset/lockout valve 40 as a result of actuation of port 9 of reset/lockout valve 40
3 connect lines 73 and 75 to each other, and similarly connect lines 87 and 76 to each other via port 94 of reset/lockout valve 40 . This condition results in compressed air being connected to the actuator 34 of FIG. is maintained in its leftward switching position. Similarly, in FIG. 5, this condition indicates that compressed air is
6, thereby maintaining the monitor valve 32 in its leftward switching position. However, these conditions are limited to the leftward switching of the monitor valve 32 in FIG.
Otherwise, the leftward switching of the monitor valve 30 in FIG. 6 does not occur. This means that in FIG. 4, compressed air from compressed air source 11 is connected through failed poppet valve assembly 48 to high actuating force actuator 35 through port 84 and line 86 to monitor valve 32. This is due to the fact that the switch is maintained in its rightward switching position. Similarly, in FIG. 6, compressed air from compressed air source 11 (due to failed poppet valve assembly 46)
Crossflow passage 54, monitor port 83, and conduit 8
5 to an actuating device 33 with a large actuating force,
Maintain monitor valve 30 in its rightward switching position. The monitor valve 32 is therefore maintained in its rightward switching position in FIG. 4 due to the fact that the pneumatically actuated device 35 is larger than or able to overcome the pneumatically actuated device 36. Similarly, the monitor valve 30 is maintained in its rightward switching position in FIG. 6 due to the fact that the pneumatically actuated device 33 is larger than or able to overcome the pneumatically actuated device 34. As a result, in either of the conditions shown in FIGS. 4 or 6, the monitor valves 30 and 32 remain out of sequence or out of sync, which is subsequently Preventing operation of control system 10, each as described in further detail above. This characteristic configuration of control system 10 therefore prevents reactivation of control system 10 by actuation of reset/lockout valve 40 concurrently with actuation of solenoids 20 and 22 until the malfunction or fault condition has been corrected. prevent.

FIGS. 7 and 9 show the monitor valve 30 or 32.
1 is a diagrammatic representation of the states of control system 10 in which one of the control system 10 is in a state of stalemate, unacceptable sluggishness, or other malfunction or failure and is out of synchronization or sequence with respect to each other. In FIGS. 7 and 9,
Both valve elements 46 and 48 of dual safety valve 12 are activated by deenergizing solenoids 20 and 22 so that conduits 82 and 81 are removed from pilot valve 16 in a manner similar to that shown in FIG.
and 18 through respective ports 63 and 65 to the discharge, resulting in a correct return to its discharge position. However, in contrast to the correct behavior shown in FIG.
The monitor valve 32 in FIG. 9 or the monitor valve 30 in FIG.
6 and 85 are stuck when being ejected or are unacceptably sluggish in their correct return to their leftward switching position.

The above-described accumulation of compressed air within volume chamber 50 causes each pneumatically actuated device 36 or 34 to malfunction or slow-moving monitor valve 32 or 34.
to the left, but only to the extent that the pressure within the volume chamber 50 does not decrease to a level at which actuation of the respective actuating device 36 or actuating device 34 is impossible. Such a decrease in volume chamber pressure is caused by an out-of-synchronization condition of the monitor valve connecting volume chamber 50 to the exhaust, as described above in connection with FIGS. 3 and 5.

The volume chamber 50 thus controls the monitor valve 30 in a manner similar to that described above for adjusting the predetermined time delay in switching the main valve element 46 or 48.
or 32 to adjust the predetermined acceptable time delay in switching appropriately. However, after such an acceptable time delay, monitor valves 30 and 32 remain in their out-of-sequence position, deactivating the system as described above in connection with FIGS. 3 and 5. This is an important innovation because it alerts the driver that there is an unacceptable fault condition or malfunction in the monitoring system, which could be caused by a malfunctioning monitoring system. If the system is allowed to continue operating, failure to detect subsequent failure or malfunction of the main valve may result. Therefore, the present invention is self-monitoring in the sense of both main valve malfunction and/or monitoring system malfunction. This feature, in addition to the nature of the monitor valve being constantly in motion, tends to prevent or minimize monitor valve malfunctions, which greatly contributes to the high reliability of the system of the present invention.

As shown in FIGS. 8 and 10, the present invention also provides that the simultaneous actuation of solenoids 20 and 22 and reset/lockout valve 40 will cause a fault to occur unless the fault condition is corrected. Prevent the system from being reactivated. In FIGS. 8 and 10, the reset/lockout valve 40 indicates that whether the out-of-synchronization condition is due to malfunction of the main valve or the monitor valve,
Each functions in the same manner as described above in FIGS. 4 and 6,
System 1 when monitor valves 30 and 32 are out of synchronization.
Prevents 0 from reactivating.

FIG. 11 shows the correct function of the reset/lockout valve 40 to reactivate the system when both the dual safety valve 12 and the monitor subsystem are corrected or in correct operating condition. There is. The reset/lockout valve 40 is switched to the left via the conduit 70.
, 72 and 73, port 93, and line 75 to connect the compressed air source 11 to the actuating devices 34 and 36, FIG.
Switch the monitor valves 30 and 32 to the left toward their correct starting position, as shown in FIG. Once in this correct starting position, manual element 42 can be released to allow reset/lockout valve 40 to be switched to the right by the force of return spring 44. Once it is lifted,
Reset/lockout valve 40 is connected to monitor valve port 60
and 57 as well as pipes 70, 72 and 74, port 92
and through lines 76, 77, 78, 79 and 88 connect the air source 11 to the volume chamber 50 for refilling. Once filled to its proper pressure level, volume chamber 50 functions to continue to maintain monitor valves 30 and 32 in the leftward switching position, thereby returning system 10 to its FIG. Proper cycling is now ready as described above in connection with FIG. However, as discussed above in connection with FIGS. 4, 6, 8 and 10, if the main poppet valve elements 46 and 48 are out of sequence, or if the monitor valves 30 and 32 are out of sequence. For example, reset/lockout valve 40 cannot perform this reset function.

As mentioned above, one skilled in the art will readily monitor the constantly moving nature of the monitor valve, the function of the dual safety valve, as well as other highly desirable features of the present invention. This book includes the self-monitoring nature of the monitor subsystem in addition to the monitor subsystem's ability to act as a buffer for the system and tolerate and adapt to predetermined levels of component sluggishness or lag. You will be able to understand the innovative and highly superior features of the invention.

The foregoing discloses and describes representative embodiments of the invention for purposes of illustration only. Those skilled in the art will appreciate from this description and from the accompanying drawings and claims that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. and it will be readily understood that modifications may be made.

[Brief explanation of the drawing]

1 is a diagram or diagram illustrating each main poppet valve element of a dual safety valve in its discharge position in an exemplary embodiment of a pneumatic actuated system with dynamic self-monitoring capabilities according to the present invention; FIG.

2 is a diagram similar to FIG. 1 except that each poppet valve element of the dual safety valve is shown in an open position for supplying compressed air to a pneumatically actuated device; FIG.

FIG. 3 shows a typical malfunction or failure condition in which the right-hand poppet valve element is stuck in its open position and is therefore out of sequence with respect to the correctly positioned left-hand poppet valve element. It is a line diagram.

4 is a diagram similar to FIG. 3 but showing the lockout/reset valve in an activated state; FIG.

FIG. 5 and FIG. 3 depicting a situation in which the left hand poppet valve element is stuck in its open position, resulting in another representative fault situation where the right hand poppet valve element is out of sequence and is correctly positioned. It is a similar figure.

6 is a diagram similar to FIG. 5 but showing the lockout/reset valve in an activated state; FIG.

7 is a diagram similar to FIGS. 1-5, but illustrating another typical malfunction or fault condition, with both poppet valve elements in correct position and in sequence with each other; FIG. , one of the monitor valves of the monitor device is stuck, malfunctioning, or otherwise impaired.

8 is a diagram similar to FIG. 7 but showing the lockout/reset valve in an activated state; FIG.

9 is a diagram similar to FIG. 7, but illustrating a condition in which the other monitor valve has become stuck, malfunctioned, or otherwise impaired; FIG.

10 is a diagram similar to FIG. 9 but showing the lockout/reset valve in an activated state; FIG.

FIG. 11 is a diagram similar to FIGS. 1-7, but illustrating a dual safety valve and monitoring system with the reset valve activated or corrected to reactivate the system;

[Explanation of symbols]

12... Control valve assembly, 27, 28... Third control valve section, 3
0, 32...Monitor valve element, monitor valve means, 37, 38...
Second control valve section, 39, 41...first control valve section, 46,
48...Control valve element, control valve means, 50...Volume chamber, 51...
Inlet, 52... Outlet, 53, 54... Intermediate pressure region, 55...
Discharge port, 83, 84...pressure detection port.

Claims (24)

[Claims] Claim 1: An inlet, an outlet, an outlet, and at least one
a control valve assembly including a pair of control valve elements, each control valve element between at least two positions for controlling the flow of compressed air between the inlet and the outlet and the outlet and the outlet; A monitoring system for a pneumatic control system, wherein said control valve elements are movable out of sequence with respect to each other and said control valve elements are moved together in sequence with each other between their respective positions. monitoring means for detecting relative movement of said control valve element and preventing further operation of said control system in response to detection of out-of-sequence movement of said control valve element; and said monitoring means for detecting malfunction of said monitoring means. A monitoring system comprising self-monitoring means for preventing further operation of said control system in response to detection of said malfunction of said control system. 2. The monitoring means includes at least one pair of monitor valve elements having port means therein, the monitor valve elements being sequenced with respect to each other between at least one pair of valve actuation positions during normal operation. said monitor means is movable together in conjunction with said monitor means means for moving said monitor valve element to an out-of-sequence position in response to detection of out-of-sequence movement of said control valve element; 2. The monitor system of claim 1, including communication means for connecting said monitor valve element to prevent further operation of said control system when said control system is out of order. 3. The monitor system of claim 2, wherein the monitor valve elements normally move in sequence with each other each time the control valve elements move in sequence with each other. 4. The monitoring means includes at least one pair of monitor valve elements having port means therein, the monitor valve elements being sequenced with each other between at least one pair of valve actuation positions during normal operation. and wherein the self-monitoring means includes communication means for connecting the monitor valve elements to prevent further operation of the control system when the monitor valve elements are out of sequence with respect to each other. The monitor system according to claim 1. 5. The monitor system of claim 4, wherein the monitor valve elements normally move in sequence with each other each time the control valve elements move in sequence with each other. 6. The method further comprising means for delaying prevention of further actuation of the control system as a result of detection of relatively out-of-sequence movement of the control valve element for a predetermined period of time. The monitor system according to item 1. 7. The monitoring system of claim 1, further comprising means for delaying said blocking of further operation of said control system as a result of detection of a malfunction of said monitoring means for a predetermined period of time. 8. The monitoring system of claim 1, further comprising means for preventing resumption of operation of the control system when the control valve elements are out of sequence with respect to each other. 9. The monitoring system of claim 1, further comprising means for preventing resumption of operation of the control system when the monitor valve elements are out of sequence with respect to each other. 10. A pair of control valve means having a pressure inlet, a supply outlet, and an outlet, each having three actuated control valve sections, a first of which each said control valve section has a pressure inlet, a supply outlet, and an outlet. a second said respective control valve section is effective for controlling communication of pressure to a respective intermediate pressure region of said each said control valve means to said supply outlet; a third said control valve means is effective for controlling communication of said supply outlet with said discharge port; a first position in which the first and second control valve parts are closed and the third control valve part is open; and a first position in which the first and second control valve parts are opened and the third control valve part is closed. respectively movable between two positions, communicating the inlet with the supply outlet and closing communication between the supply outlet and the outlet when both of the control valve means are in their respective second positions; Both said control valve means have their respective first
position closes communication between said inlet and said intermediate pressure region, closes communication between said intermediate pressure region and said supply outlet, and opens communication between said supply outlet and said discharge port, one of said control valve means Apparatus for detecting a malfunction in a pneumatic control system for a press or similar device, wherein said control valve means are in different out-of-sequence positions with respect to each other, wherein said control valve means prevents communication of said inlet pressure to said supply outlet when not in a second position. in response to the actual pressure to provide a malfunction signal when the control valve means are out of sequence with respect to each other and to prevent further operation of the control system. monitor means for detecting the pressure of the control valve means, said monitor means including at least one pair of monitor valve means each having a port means therein, said monitor valve means being such that during normal operation said control valve means are in contact with each other; If the sequence matches, the first
and said monitor valve means are movable together in sequence between each of the at least one pair of valve actuation positions, one of said monitor valve means being one of said intermediate pressure regions; the other of said monitor valve means being at least partially movable in response to said detection of a pressure of the other of said intermediate pressure region; the means includes means for moving the monitor valve means to different out-of-sequence positions in response to different pressures in the intermediate pressure region, and the monitor valve means are in different out-of-sequence positions with respect to each other. fluid communication means connecting said monitor valve means to prevent further operation of said control system in response to said control system. 11. When the monitor valve means is in a normal state, the control valve means move together in sequence each time the control valve means move together in sequence.
0. 12. The monitor means is configured to control the control system in response to the monitor valve means being in different out-of-sequence positions with respect to whether the control valve means are out-of-sequence with respect to each other. 12. The apparatus of claim 11, further comprising means for preventing further actuation. 13. Said monitor means for delaying a predetermined period of time to prevent further operation of said control system as a result of said monitor valve means being in said different positions out of sequence with respect to each other. 13. The device of claim 12, further comprising damping means. 14. The buffer means includes a volume chamber for storing a predetermined amount of compressed air, the volume chamber being in fluid communication with both of the monitor valve means, and the monitor valve means comprising 14. The device according to claim 13, wherein the device is also movable in response to pressure. 15. The apparatus of claim 14, further comprising means for preventing resumption of operation of the control system when the control valve means are out of sequence with respect to each other. 16. The apparatus of claim 15 further comprising means for preventing resumption of operation of said control system when said monitor valve means are out of sequence with respect to each other. 17. A pair of control valve means each having a pressure inlet, a supply outlet, and an outlet and three actuated control valve sections, a first of which each control valve section has a pressure inlet, a supply outlet, and an outlet. a second said respective control valve section is effective for controlling communication of pressure to a respective intermediate pressure region of said each said control valve means to said supply outlet; a third said control valve means is effective for controlling communication of said supply outlet with said discharge port; a first position in which the first and second control valve parts are closed and the third control valve part is open; and a first position in which the first and second control valve parts are opened and the third control valve part is closed. respectively movable between two positions, communicating the inlet with the supply outlet and closing communication between the supply outlet and the outlet when both of the control valve means are in their respective second positions; Both said control valve means have their respective first
position closes communication between said inlet and said intermediate pressure region, closes communication between said intermediate pressure region and said supply outlet, and opens communication between said supply outlet and said discharge port, one of said control valve means Apparatus for detecting a malfunction in a pneumatic control system for a press or similar device, wherein said control valve means are in different out-of-sequence positions with respect to each other, wherein said control valve means prevents communication of said inlet pressure to said supply outlet when not in a second position. monitor means for detecting the pressure in said intermediate pressure region in response to actual pressure, and said means for detecting said pressure in order to provide a malfunction signal when said pressure is in one of said intermediate pressure regions of each control valve means. each pair of pressure sensing ports extending from the pressure sensing means to the monitoring means;
The monitoring means is configured to: in response to a malfunction signal of the control valve means, or in response to a malfunction of the monitor means itself, regardless of whether a malfunction exists in the control valve means;
An improvement consisting of including means for preventing further operation of said control system. 18. The monitor means includes at least one pair of movable monitor valve means, the monitor valve means comprising:
18. The apparatus of claim 17, wherein each time said control valve means move together in sequence with each other each time said control valve means move together in sequence with each other. 19. The apparatus of claim 18, wherein said monitoring means includes means for moving said monitor valve means to different out-of-sequence positions in response to a malfunction of said control valve means. 20. The monitor means is configured to control the control system in response to the monitor valve means being in different out-of-sequence positions, regardless of whether the control valve means are out-of-sequence with respect to each other. 20. The apparatus of claim 19 further comprising means for preventing further actuation. 21. Said monitoring means for delaying a predetermined period of time to prevent further operation of said control system as a result of said monitoring valve means being in said different positions out of sequence with respect to each other. 21. The apparatus of claim 20, further comprising damping means. 22. The buffer means includes a volume chamber for storing a predetermined amount of compressed air, the volume chamber being in fluid communication with both of the monitor valve means, the monitor valve means being in fluid communication with both of the volume chambers. 22. The device of claim 21, wherein the device is also movable in response to pressure. 23. The apparatus of claim 22 further comprising means for preventing resumption of operation of said control system when said control valve means are out of sequence with respect to each other. 24. The apparatus of claim 23 further comprising means for preventing resumption of operation of said control system when said monitor valve means are out of sequence with respect to each other.